Adjusting IOVDD voltage to nRF7002 for alternate MCU GPIO voltages

[chris_h]

Hi,

I have a hardware question regarding IOVDD on the nRF7002 IC. I'm planning on using the nRF5340, in high voltage mode, connected to the nRF7002 as seen in the recommended configuration on page 43 of 7002 PS v1.0.

nRF5340 high voltage mode allows me to adjust VDD between 1.8V and 3.3V, default at 1.8V.

As seen in the table below from 7002 PS v1.0 pg32, IOVDD has an allowable input voltage of up to 3.6V. 

To the question:

1. I have a requirement to supply a UART from my nRF5340 at 3V IO voltage.  Will adjusting my nRF5340 VDD to 3V, which is technically within the 7002 IOVDD range as seen in the table above, be allowed? 
2. By the same logic, could I use nRF5340 normal voltage mode at 3V (which maintains VDD at 3V as well), in the same way i.e. supplying the 7002 IOVDD at 3V?

If this is not recommended, could you please let me know why and what the suggested alternatives are?  (voltage level shifters on UART?)

Thanks in advance!

Chris

[ketiljo]

Hi Crist

You can either set VDD of the nRF5340 to 3.0 V (in high voltage mopde) and use that to supply IOVDD of the nRF7002 or use the nRF5340 in normal voltage mode with an external supply of 3.0 V. IOVDD can be between 1.62 and 3.6 V as you say. 

Best regards,

Ketil Aas-Johansen

[chris_h]

Hi Ketil - thank you for the answer!